switch_root: error_msg -> perror_msg, reduce by 22 bytes while at it.

diff --git a/util-linux/switch_root.c b/util-linux/switch_root.c
index 6dba9f05f6539acde6cc871c2c800f82c649389c..88bb9db2a67e92ff9c36028ee2c36209fc6cefa6 100644 (file)
--- a/util-linux/switch_root.c
+++ b/util-linux/switch_root.c
@@ -75,14 +75,14 @@ int switch_root_main(int argc, char **argv)
 
        opt_complementary = "-2";
        getopt32(argc, argv, "c:", &console);
+       argv += optind;
 
        // Change to new root directory and verify it's a different fs.
 
-       newroot = argv[optind++];
+       newroot = *argv++;
 
-       if (chdir(newroot) || lstat(".", &st1) || lstat("/", &st2) ||
-               st1.st_dev == st2.st_dev)
-       {
+       xchdir(newroot);
+       if (lstat(".", &st1) || lstat("/", &st2) || st1.st_dev == st2.st_dev) {
                bb_error_msg_and_die("bad newroot %s", newroot);
        }
        rootdev = st2.st_dev;
@@ -105,8 +105,9 @@ int switch_root_main(int argc, char **argv)
        // Overmount / with newdir and chroot into it.  The chdir is needed to
        // recalculate "." and ".." links.
 
-       if (mount(".", "/", NULL, MS_MOVE, NULL) || chroot(".") || chdir("/"))
+       if (mount(".", "/", NULL, MS_MOVE, NULL) || chroot("."))
                bb_error_msg_and_die("error moving root");
+       xchdir("/");
 
        // If a new console specified, redirect stdin/stdout/stderr to that.
 
@@ -118,6 +119,6 @@ int switch_root_main(int argc, char **argv)
        }
 
        // Exec real init.  (This is why we must be pid 1.)
-       execv(argv[optind], argv+optind);
-       bb_error_msg_and_die("bad init '%s'", argv[optind]);
+       execv(argv[0], argv);
+       bb_perror_msg_and_die("bad init %s", argv[0]);
 }